Hydrocarbon treating process



United States Patent 6 a HYDROCARBON TREATING PROCESS Chyn Duog Shiah, New York, N. Y.

No Drawing. Application December 6, 1951,

Serial No. 260,313

7 Claims. (Cl. 196-23) This invention relates to the treatment of hydrocarbon oils and is more particularly concerned with the treatment of such oils with coordination compounds of boron fluoride (BFs).

The purification of hydrocarbon oil stocks by removal of undesired constituents is an ever-present problem in the petroleum refining industry and many purification processes have been proposed. The removal of various constituents from hydrocarbon oils not only increases the value of the oils but makes them more useful and in some cases easier to handle.

For example, low sulfur crude oils always command a better price than high sulfur crudes. Further, it is easier and more economical to process lower sulfur crude oil, because less alloy protection is required. The overall properties of products such as the color, octane number and lead susceptibility of the gasoline are generally higher. Since current trends in the petroleum industry point to the increasing use of high sulfur crude oils, the direct desulfurization of crude oil is becoming more and more important. Hughes et al. (Ind. & Eng. Chem. 42 1879 (1950)) suggested the use of hydrogenation for desulfurization only after concluding that less expensive methods were unsatisfactory. Hale et a1. (Ind. & Eng. Chem. 41 2702 (1949)) suggested bauxite treatment at 750 F. This method is expensive and not generally applicable to heavy crudes (Burk, U. S. Patent 2,343,841 (1944); 2,343,744 (1944)). Hughes et al. (Ind. & Eng. Chem. 43 750 (1951)) used a mixture of boron fluoride and hydrogen fluoride as a sulfur extractive agent. The sulfur removal is satisfactory but the yield is low. In addition their extractive agent is highly corrosive and requires pressure in handling.

In the case of lighter distillates such as gasoline, the removal of sulfur increases both the octane number and the lead susceptibility. Numerous methods have been proposed for the removal of mercaptans but few for cyclic sulfur compounds. Axe (U. S. Patent 2,416,465) suggested the use of boron fiuoride hydrate as an extractive agent for sulfur removal from light products. Unfortunately, the recovery of the agent is difficult.

'Ihe asphaltic constituents in crude oil or other hydrocarbon stocks are undesirable except for use in the manufacture of commercial asphalts. If the crude oil is to be used for the production of light products and as a cracking plant charging stock, especially in a catalytic cracking plant, the asphaltic substances and carbon-like substances are first removed by one of the following four known processes: 1. Coking-which is objectionable because of high investment and troublesome handling of the coke produced, sometimes necessitating mechanical or hydraulic decoking; 2. Vacuum distillation-which has serious limitations owing to the fact that when a high vacuum is used the process becomes uneconomical, while if a relatively low vacuum is used the yield of catalytic cracker charging stock is too low; 3. Propane deasphalting or decarbonizingwhich requires a solvent oil ratio of at least 3 to 1 and also involves pressure operation; and 4. Sulfuric acid 2,745,792 Patented May 15, 1956 treatment-which has now become practically obsolete because of operating disadvantages. In the manufacture of lubricating stocks from suitable crude oils, deasphalting and decarbonizing are also necessary steps.

The presence of nitrogen compounds is objectionable in all petroleum and petroleum-like products, especially in catalytic cracker charging stock, because the nitrogen compounds are very effective catalyst poisons. One of the main difiiculties in the economical processing of shale oil is its high nitrogen content. No commercially feasible method has been heretofore proposed for the removal of nitrogen except by pressure hydrogenation.

Oxygenated compounds are also objectionable since they lower the heating value of the oil and promote the formation of acids or peroxides, which are corrosive.

Unsaturated compounds occur in various petroleum products. The unstable unsaturated compounds such as diolefins and acetylenes, which occur only in minor amounts in cracked gasoline, are undesirable, while the mono-olefins in cracked gasoline and/or Fisher-Tropsch synthetic gasoline are highly desirable as motor fuel.

Color bodies of various types are found in hydrocarbon bodies and are generally considered objectionable.

One object of this invention is the provision of an improved process for the removal from hydrocarbon oil stocks of deleterious and/or undesirable constituents such as asphaltic compounds, or more specifically colloidal carbons, carboids, carbenes, asphaltenes, resins and the like.

Another object of the invention is to provide a process for improving the qualities of hydrocarbon oil stocks by the removal of sulfur compounds, especially those of cyclic nature and/ or of high molecular weights.

A further object of this invention is to provide a process for improving the quality of hydrocarbon stocks by the removal of nitrogen compounds.

An additional object of the invention is to provide a process for removing oxygen compounds from hydrocarbon oil stocks.

A still further object of the invention is the provision of a process for removing unstable unsaturated compounds from hydrocarbon oil stocks Without affecting the stable unsaturated compounds therein.

Another object of the invention is to provide a process for improving hydrocarbon oils by removing color bodies therefrom.

In accordance with the invention, I treat the hydrocarbon oil stock with a coordination compound of boron fluoride (BFa) to elfect reaction between the boron fluoride coordination compound and the undesired constituents of the hydrocarbon oil being treated. The boron fluoride coordination compound is used in an amount corresponding to at least 0.1% by volume, preferably 0.5 to 25% by volume of the oil treated, and is intimately mixed with the hydrocarbon oil for a short period of time, e. g. one-half minute to thirty minutes, and the oil is then separated from the boron fluoride reaction products. The boron fluoride coordination compound and the associated constituents of the oil stratify as a coalesced phase and the refined hydrocarbon oil forms a purified phase. The coalesced phase is readily separated by decantation, centrifuging or other convenient means, from the purified phase and the boron fluoride coordination compound separated from the coalesced phase. The refined oil which forms the purified phase is then processed in the usual manner.

It is a feature of my invention that the treatment with the boron fluoride coordination compound results in the selective removal, when present in the hydrocarbon oil treated, of asphaltic constituents, particularly colloidal carbons, carboids, carbenes, asphaltenes, resins and the like, sulfur compounds, particularly cyclic sulfur compounds and high molecular weight sulfur compounds, nitrogen compounds, oxygen compounds, color bodies and unstable unsaturated compounds.

It is a further feature of my process that the treatment with theboron fluoride coordination compound results in the selective removal of unstable, unsaturated compounds, as mentioned, without aflecting or removing the stable unsaturated compounds.

It is a further feature of my invention that the boron fluoride coordination compound treatment is applicable to and eflective upon a wide variety of hydrocarbon oils such as crude oil, straight run gasoline, kerosene, diesel oil, lubricating oil stocks, charging stock of petroleum origin for catalytic crackers, coal-tar and coal-tar distillates, liquid petroleum-like products from the hydrogenation of solid fuels such as coal, shale oil and shale oil distillates, oil from tar sands, other synthetic liquid fuel products and the like. The foregoing list of products to which the invention is applicable is illustrative only and other hydrocarbon oil materials may be eflectively treated in accordance with my invention.

For example, treatment with boron fluoride coordination compounds in accordance with my invention is particularly suitable for the reclaiming of used lubricating oils, e. g. dirty lubricating oils removed from the crank cases of motor vehicles. In accordance with my process, the used lubricating oil may be restored to substantially its original state. Furthermore, since it is a general tendency that these undesirable constituents tend to concentrate in the higher molecular weight portion of the oil, their removal by means of a boron fluoride coordination compound tends to lower the specific gravity of the oil. Some of these high molecular weight constituents removed are coloring matters. Thus by this treatment the color of the treated hydrocarbon stock is generally improved. In heavy oils such as lubricating oil stock a distinct bloom is produced.

Since my process is particularly efiective, as mentioned, for removing asphalts, sulfur compounds, carbon, oxygen compounds and nitrogen compounds, it may be conveniently referred to as a process of de-asconing. The action of the boron fluoride coordination compound in accordance with the invention is not limited, however, in its utility to the removal of the above mentioned undesired constituents but is efiiective, for example, in separating light aromatic compounds from paraffins and naphtheness and in the improvement of the viscosity index and viscosity gravity content of a lubricating oil stock by increasing its paraflinicity.

After the removal of the coalesced phase from the reaction mixture, not only may the coalesced phase be used for recovery of the boron fluoride coordination compound employed but it may be used as a source of commercially valuable forms of the extracted impurities. For example, the sulfur removed from high sulfur crude oils by treatment of the oils in accordance with my invention is concentrated in a relatively small fraction after treatment and the recovery of elemental sulfur is easily effected. My invention, therefore, provides a means for economically recovering elementary sulfur from hydrocarbon oils.

Other objects and features of my invention will be readily apparent to those skilled in the art from the following detailed description of my hydrocarbon oil treating process.

The theoretical background of the invention involves the well known property of boron fluoride of forming many coordination compounds or adducts, as they are sometimes called. Actually the number of such coordination compounds is very great, whereas the number of difierent atoms which have been found to donate electron pairs to the boron atom is rather small. Within this exclusive group, however, are nitrogen, oxygen, sulfur and carbon. Boron fluoride is a very eflicient catalyst in many reactions.

The prevailing theory is that its catalytic activity is based on the electrophilic character of the boron fluoride molecule. As a consequence of its behavior as an acid it is assumed to react with an organic molecule which acts as a base to produce a coordination compound. The molecular boron fluoride is then assumed to ionize in such manner that the acidity of the medium is increased. The organic molecule then reacts to form the desired product with the regeneration of a coordination compound of boron trifluoride. However, since the reaction of BFs is rather vigorous, and since it is a gas and thus rather diflicult to handle and recover, various modifiers or moderators or carriers for BFa have been proposed. For example, di-ethyl ether-boron fluoride is a liquid which is now available in commercial quantities. Its catalytic behavior may be postulated as follows:

(CzH5)20 BFS' (Base) (acid) Thus solvated protons are liberated.

In accordance with my invention I employ coordination compounds of boron fluoride with alcohols, ethers, ketones, esters, acid anhydrides, aldehydes and nitrogen compounds such as ammonia, amines, amides, amino alcohols and anilides. Examples of suitable boron fluoride coordination compounds with alcohols are:

Methyl alcohol boron fluoride (BFa-CHaOH) Ethyl alcohol boron fluoride (BFs- CHsCHaOH) Propyl alcohol boron fluoride (BF3CH3CH2CH2OH) Butyl alcohol boron fluoride BF3'CH3(CH2)CH2OH Phenol boron fluoride (BFs-CsHsOH) Cresol boron fluoride (BF3-CH3CsH4OH) Examples of suitable boron fluoride coordination compounds with ethers are:

Examples of boron fluoride coordination compounds with ketones suitable for use in accordance with my invention are:

Acetone boron fluoride (BFs-CHaCOCHs) Methylethylketone boron fluoride (BFzrCHsCOCzHs) Diethylketone boron fluoride (BFs-CzHsCOCzHs) Examples of suitable boron fluoride coordination compounds with esters are:

Methyl formate boron fluoride (BFa-HCOOCI-Is) Ethyl formate boron fluoride (BFs-HCOOCzHs) Ethyl acetate boron fluoride (BFs-CHsCOOCzHs) Ethyl propionate boron fluoride (BF3 CHsCHzCOOCzHs) Methyl benzoate boron fluoride (BFrCsI-IsCOOCI-Is) Examples of suitable boron fluoride coordination compounds with acid anhydrides are:

Propionic anhydride boron fluoride (BFs- (CH3CH2CO)2O) Butyric anhydride boron fluoride (BF3 CHsCI-IaCHzCO )20) Isobutyric anhydride boron fluoride (BFs- (CH3)2(CHCO)2O) Examples of suitable boron fluoride coordination compounds with aldehydes are:

Acetaldehyde boron fluoride (BFa-CHaCI-IO) Chloral boron fluoride (BFa-CClsCHO) Phenyl acetaldehyde boron fluoride (BFs-CaHsCI-IzCHO) Examples of suitable boron fluoride coordination compounds with acids are:

Formic acid boron fluoride (BFs-HCOOH) Acetic acid boron fluoride (BFs-CHsCOOI-I) Propionic acid boron fluoride (BFS'CHBCH2COOH) Salicylic acid boron fluoride (BF3'HOC6H4COOH) Benzoic acid boron fluoride (BFs-CsHsCOOH) Examples of suitable boron fluoride coordination compounds with nitrogen compounds, e. 'g'. ammonia, amines, amides, anilides, and amino alcohols, are:

Ammonia boron fluoride (BFs-NI-Ia) Methylamine boron fluoride (BFs-CHaNHz) Aniline boron fluoride (BFs-CsHsNHz) Ethanolamine boron fluoride (BF3NH2CH2CH2OH) Acetanilide boron fluoride (BF3'CH3CONHC6H5) Propionamide boron fluoride (BF3'CH3CH2CONH2) The boron fluoride coordination compounds which I employ should be either liquid or solid at normal room temperatures, i. e. 20 C. If the coordination compound is a liquid, it should have a specific gravity greater than 1, and should preferably vaporize below 140 C. at 760 mm. pressure. Solid coordination compounds are suitable if they are non-hygroscopic and relatively stable.

While any boron fluoride coordination compounds falling within the foregoing definitions are suitable for use in accordance with my invention, I preferably employ, and have found particularly effective, boron fluoride coordination compounds with ethers, boron fluoride coordination compounds with alcohols, and boron fluoride coordination compound with nitrogen compounds, more particularly diethylether boron fluoride, phenol boron fluoride, and acetanilide boron fluoride.

In accordance with the invention, as soon as the sulfur, nitrogen and oxygen-containing compounds have had an opportunity to react with BFa, either as a molecule or as a part of the coordination compound added to the oil, a new series of coordination compounds is formed and separates out from the purified oil, either in solid form or semi-solid form in admixture with or in solution in the added agent. The reaction is almost instantaneous when intimate contact is provided. It will be understood that I consider within the scope of my invention the use of any boron fluoride coordination compound and that I do not limit myself to the specific compounds listed above, which are intended merely as illustrative. Furthermore, it is not necessary to use only one of the coordination compounds but mixtures of two or more may also suitably be used, although there is generally noparticular need for using mixtures.

Inasmuch as the amount of undesirable compounds in the oil treated is relatively small, as a rule totaling not more than 10%, excluding asphalt, it follows naturally that the amount of agent required can be small. As previously mentioned, at least 0.1 volume per cent, preferably 0.5 to 25 volume per cent, of the coordination compound is used. It will be understood that the quantity of boron fluoride coordination compound used will vary from oil to oil depending upon the nature of the materials to be removed. For example, when the process of the invention is used for separating aromatic hydrocarbons from mixtures containing the aromatic hydrocarbons in admixture with non-aromatic hydrocarbons, e. g. paraflins and naphthenes, a large excess of the boron fluoride coordination compound is advantageously used. Thus, the ratio of coordination compound to oil may vary from about 0.5 to l to 10 to 1, although in most cases a coordination compound to oil ratio of 5:1 is suflicient.

The temperature at which I carry out my process is in most instances, room temperature or slightly below, e. g. 15 C. However, when relatively viscous oils are treated it is desirable to heat them to a readily flowable state, e. g. by heating them up to about 60 C. In general, therefore, my process is carried out at temperatures of about 15 C. to 60 C. Alternatively or concurrently, I may dilute the viscous oil with an inert solvent such as a paraflinic or naphthenic hydrocarbon or hydrocarbon fraction, e. g. n-heptane, n-hexane and cyclohexane.

The contact between the boron fluoride coordination compound and the oil needs only to be sufficient to permit the coordination compound to react to effect separation of the undesired constituents from the oil. Generally speaking, the contact time is between one-half minute and thirty minutes, although longer contact times may be utilized without departing from the scope of the invention.

While I do not mean to be bound by any particular theory with respect to the reactions involved between the oil treated and the boron fluoride coordination compound in accordance with my process, the suprising action of the coordination compounds in removing asphaltic substances is apparently due to the fact that the asphaltic substances in crude oils may be considered as forming with the oils a colloidal system with resinous materials serving as protective colloids. The boron fluoride coordination compounds, e. g. di-ethyl ether-boron fluoride, and the like, react with the resins to form other coordination compounds and thus remove the protective colloid from the system, thereby forcing the asphaltenes and like asphaltic constituents to coalesce and pass into the coalesced phase.

Similarly, in the case of sulfur removal in accordance with my invention, I believe that the boron fluoride coordination compounds employed form coordination compounds with the sulfur bodies in the oil treated and thus the reaction may be considered as a pseudo-chemical reaction as distinct from the purely physical action of commercial sulfur, e. g. mercaptan, removal processes or the chemical action of catalytic hydrodesulfurization. The boron fluoride coordination compounds make no distinction among mercaptans, sulfides and cyclic sulfur compounds, such as thiophene, and the relative quantities of each removed are governed solely by mass action law.

It is known that boron fluoride coordination compounds, such as di-ethyl ether-boron fluoride are powerful polymerization catalysts. However, in accordance with my invention wherein my refining or deasconing treatment is carried out at low temperature, e. g. room temperature and at normal atmospheric pressure, the polymerization of the desirable mono-olefins is avoided while polymerization of the undesired diolefins and acetylenes is promoted.

I have also found that boron fluoride coordination compounds exhibit a preferential atfinity for aromatic compounds over paraflinic and naphthenic compounds. Thus, my process provides a new method of separating aromatic compounds from paraflinic and naphthenic compounds. When applied to lubricating oil stocks, my process serves to increase the paralflnicity of the stock by selectively extracting the more aromatic constituents.

As previously mentioned, the product resulting from treatment of a hydrocarbon oil in accordance with my process will stratify or can be readily separated into two distinct phases. As may be seen from the following table,

the commonly available boron fluoride coordination compounds have a relatively high specific gravity compared with the usual hydrocarbon stocks. Their boiling points are also within a relatively low range so that their recovery from the extract for reuse is a relatively simple matter.

As previously mentioned, the coalesced phase conof the upper layer which comprises the refined oil, were then determined, and a sample of the crude oil treated, with the following results:

taining the impurities may be separated from the purified phase by any convenient means, e. g. decantation, centrifuging and the like. Similarly, known methods of liquid-liquid extraction either batch-operated or continuous, such as the well known Podbielniak centrifugal contactor, may be used.

All boron fluoride coordination compounds decompose somewhat upon heating even before reaching their boiling point but the decomposition products tend to recombine readily when the temperature is lowered. This property makes it possible to effect eflicient recovery of the liquid agents which I employ by simple distillation. However, I prefer to use vacuum distillation, or more conveniently, partial pressure distillation, with the addition of an inert light solvent such as cyclohexane or a fraction of parafimic or naphthenic hydrocarbon distillate boiling in the range of 60100 C. to the used agent, and then subjecting the mixture to distillation. The recovered agent, such as BFa (C2H5)2O, will distill over together with the light solvent. The distillate immediately separates into two layers. The lower layer being the recovered reagent. The recovery, in the laboratory, has been found to be better than 99%, mechanical transfer losses notwithstanding.

Solid boron fluoride coordination compounds which are not readily separated by distillation, e. g. acetanilide, are advantageously separated by means of an oxygenated solvent e. g. a ketone, an alcohol or an ether, such as acetone, ethyl alcohol and diethyl ether, which preferentially dissolves the coordination compound. The dissolved boron fluoride coordination compound is suitably recovered by recrystallization by the addition to the solution of a second solvent which is a non-solvent for the coordination compound in known manner, or by evaporation of the solvent. Alternatively, but less desirably, the petroleum residual material may be leached from the coalesced phase by means of a petroleum hydrocarbon solvent, e. g. petroleum ether, or benzene, leaving the boron fluoride coordination behind.

To remove the traces of ER; compounds from the treated hydrocarbon stock, a step which in most instances is not necessary, I prefer-to percolate the oil through a layer of cryolite or sodium fluoride with or without the admixture of percolation clay. The last trace of BFs forms sodium fluoborate which can be easily leached out from the bed by water and recovered.

The following examples will serve to illustrate more fully the operation and advantages of the present invention:

Example I To three samples each comprising 80 volume parts of 38 API Saudi Arabia crude oil were added, respectively, 0.5, 1, and 2 volume parts of diethyl ether-boron fluoride at room temperature. Each sample was shaken vigorously for five minutes. After settling, the upper layer was decanted and percolated through cryolite. The specific gravity, Conradson carbon residue and sulfur content The lower layer in each is semi-solid and asphaltic in character.

Since this particular crude yielded approximately 7% asphalt by vacuum distillation, it can be considered that essentially all the asphalt in the oil was removed by this simple treatment and the yield of oil was high. The specific gravity of the oil was lowered to the extent of more than 1 API and its color much improved.

The lower strata (the coelesced strata) from the three samples were combined and diluted with 50 volume parts of methylcyclo-hexane and distilled. A 99.5% recovery of BFs ethyl-ether was obtained. The residue was found to be a soft asphalt with a softening point of F.

Example II A sample comprising 30 cc. of a heavy Santa Maria crude oil was diluted with 50 cc. of n-heptane at room temperature. Analysis of the Santa Maria crude oil showed that it had a sulfur content of 4.88% and a Conradson carbon residue of 22%. To the diluted oil were added 2 grams of boron fiuoride-acetanilide crystals, and the oil and crystals were thoroughly mixed for five minutes. The mixture was then filtered, the refined oil being obtained as the filtrate. Analysis of the filtrate oil showed that the sulfur content had been reduced to 1.91% and that the Conradson carbon residue had been reduced to 7.49%.

As previously mentioned, a solid boron fluoride coordination compound is conveniently recovered from the associated impurities which have been removed from the oil treated by treating the residue with an oxygenated solvent. In the foregoing example, the boron fluorideacetanilide was recovered in pure form by treatment of the residuewith acetone followed by evaporation of the solvent. Equally effective results can be obtained with ethyl alcohol or other like solvent.

Example 111 The same crude oil described in Example I was distilled up to 275 C. The distillate was a mixture of gasoline, kerosene and light diesel oil and had a light brown color. This distillate was shaken with 20% by volume of BF3-(CzI-I5)2O. The product, without decreasing in volume, became water white. The boron fluoride diethyl ether was recovered by dilution with methyl cyclohexane followed by distillation as described in Example I.

Example IV This example illustrates the use of the process of the invention for separating aromatic compounds from hydrocarbon mixtures containing aromatic and non-aromatic constituents. A mixture was made from 5 volume parts of toluene and 5 volume parts of a petroleum ether.

parts. All of the toluene was found to have become associated with the boron fluoride diethyl ether in the lower stratum while the petroleum ether in the upper stratum was substantially free from toluene. In connection with Example IV, preliminary experiments showed that when a boron fluoride coordination compound, e. g. boron fluoride diethyl ether is mixed with an aromatic hydrocarbon such as benzene, toluene, ethyl benzene and xylene, complete miscibility is obtained even when the coordination compound to oil ratio is raised as high as to 2, whereas non-miscibility is obtained when the boron fluoride coordination compound is mixed with a paratflnic or naphthenic hydrocarbon oil such as petroleum ether or methyl cyclohexane.

It will be obvious to those skilled in the art that various changes and modifications may be made in the process hereinabove described without departing from the scope of the invention as defined in the appended claims and it is intended, therefore, that all matter contained in the foregoing description shall be interpreted as illustrative only and not in a limiting sense.

What I claim and desire to secure by Letters Patent is:

l. A process of treating a heavy hydrocarbon oil stock characterized by a significant content of asphalts and colloidal carbon to remove said asphalts and carbon from said stock which comprises, intimately mixing said heavy hydrocarbon oil stock at substantially atmospheric pressure with a coalescing agent comprising a coordination compound of boron fluoride in the substantial absence of free boron fluoride and free coordination component, said coalescing agent being employed in a quantity of at least about 0.1% by volume but substantially less than the quantity required for solvent separation of said asphalts and colloidal carbon from said heavy hdrocarbon oil stock, causing the intimately mixed stock to separate into a coalesced phase and a purified phase, and separating said purified phase from said coalesced phase.

2. A process of treating a heavy hydrocarbon oil stock characterized by a significant content of asphalts and colloidal carbon to remove said asphalts and carbon from said stock which comprises, intimately mixing said heavy hydrocarbon oil stock at substantially atmospheric pressure for /2 minute to 30 minutes with a coalescing agent comprising a coordination compound of boron fluoride in the substantial absence of free boron fluoride and free coordination component, said coalescing agent being employed in a quantity of at least about 0.1% by volume but substantially less than the quantity required for solvent separation of said asphalts and colloidal carbon from said heavy hydrocarbon oil stock, causing the intimately mixed stock to separate into a coalesced phase and a purified phase, and separating said purified phase from said coalesced phase.

3. A process of treating a heavy hydrocarbon oil stock characterized by a significant content of asphalts and colloidal carbon to remove said asphalts and carbon from said stock which comprises, intimately mixing said heavy hydrocarbon oil stock at substantially atmospheric pressure with a coalescing agent comprising a coordination compound of boron fluoride in the substantial absence of free boron fluoride and free coordination component, said coalescing agent being employed in a quantity of about 0.1% to 25% by volume of heavy hydrocarbon oil stock, causing the intimately mixed stock to separate into a coalesced phase and a purified phase, and separating said purified phase from said coalesced phase.

4. A process of treating a heavy hydrocarbon oil stock characterized by a significant content of asphalts and colloidal carbon to remove said asphalts and carbon from said stock which comprises, intimately mixing said heavy hydrocarbon oil stock at substantially atmospheric pressure at a temperature between about 15 C. and 60 C. with a coalescing agent comprising a coordination compound of boron fluoride in the substantial absence of free boron fluoride and free coordination component, said coalescing agent being employed in a quantity of at least about 0.1% by volume but substantially less than the quantity required for solvent separation of said asphalts and colloidal carbon from said heavy hydrocarbon oil stock, causing the intimately mixed stock to separate into a coalesced phase and a purified phase, and separating said purified phase from said coalesced phase.

5. A process of treating a heavy hydrocarbon oil stock characterized by a significant content of asphalts and colloidal carbon to remove said asphalts and carbon from said stock which comprises, intimately mixing said heavy hydrocarbon oil stock at substantially atmospheric pressure at a temperature between about 15 C. and 60 C. for /2 minute to 30 minutes with a coalescing agent comprising a coordination compound of boron fluoride in the substantial absence of free boron fluoride and free coordination component, said coalescing agent being employed in a quantity of about 0.1% to 25 by volume of said heavy hydrocarbon oil stock, causing the intimately mixed stock to separate into a coalesced phase and a purified phase, and separating said purified phase from said coalesced phase.

6. A process of treating a heavy hydrocarbon oil stock characterized by a significant content of asphalts and colloidal carbon to remove said asphalts and carbon from said stock which comprises, intimately mixing said heavy hydrocarbon oil stock at substantially atmospheric pressure at a temperature between about 15 C. and 60 C. for /2 minute to 30 minutes with a coalescing agent comprising a liquid coordination compound of boron fluoride in the substantial absence of free boron fluoride and free coordination component, said coalescing agent being employed in a quantity of at least about 0.1% by volume but substantially less than the quantity required for solvent separation of said asphalts and colloidal carbon from said heavy hydrocarbon oil stock, causing the intimately mixed stock to separate into a coalesced phase and a purified phase, and separating said purified phase from said coalesced phase.

7. A process of treating a heavy hydrocarbon oil stock characterized by a significant content of asphalts and colloidal carbon to remove said asphalts and carbon from said stock which comprises, intimately mixing said heavy hydrocarbon oil stock at substantially atmospheric pressure at a temperature between about 15 C. and 60 C. for /2 minute to 30 minutes with a coalescing agent comprising a liquid coordination compound of boron fluoride in the substantial absence of free boron fluoride and free coordination component, said coalescing agent being employed in a quantity of at least about 0.1% by volume but substantially less than the quantity required for solvent separation of said asphalts and colloidal carbon from said heavy hydrocarbon oil stock, causing the intimately mixed stock to separate into a coalesced phase and a purified phase, separating said purified phase from said coalesced phase, and recovering the boron fluoride coordination compound from said coalesced phase.

References Cited in the file of this patent UNITED STATES PATENTS 2,415,171 Horeczy Feb. 4, 1947 2,495,851 Lien et a1 Jan. 31, 1950 2,495,852 Lien et a1. Jan. 31, 1950 2,639,262 Kennedy et al. May 19, 1953 2,657,175 Mason Oct. 27, 1953 

1. A PROCESS OF TREATING A HEAVY HYDROCARBON OIL STOCK CHARACTERIZED BY A SIGNIFICANT CONTENT OF ASPHALTS AND COLLOIDAL CARBON TO REMOVE SAID ASPHALTS AND CARBON FROM SAID STOCK WHICH COMPRISES, INTIMATELY MIXING SAID HEAVY HYDROCARBON OIL STOCK AT SUBSTANTIALLY ATMOSPHERIC PRESSURE WITH A COALESCING AGENT COMPRISING A COORDINATION COMPOUND OF BORON FLUORIDE IN THE SUBSTANTIAL ABSENCE OF FREE BORON FLUORIDE AND FREE COORDINATION COMPONENT, SAID COALESCING AGENT BEING EMPLOYED IN A QUANTITY OF AT LEAST ABOUT 0.1% BY VOLUME BUT SUBSTANTIALLY LESS THAN THE QUANTITY REQUIRED FOR SOLVENT SEPARATION OF SAID ASPHALTS AND COLLOIDAL CARBON FROM SAID HEAVY HYDROCARBON OIL STOCK, CAUSING THE INTIMATELY MIXED STOCK TO SEPARATE INTO A COALESCED PHASE AND A PURIFIED PHASE, AND SEPARATING SAID PURIFIED PHASE FROM SAID COALESCED PHASE. 